Rod and stem C4
One key's resonator from the side: the glass rod clamped on its steel stem, the tuning weight with it, the stem bolted to the collector below and the frame above. The finger strokes along the rod; it glows while it sticks to the glass, once a cycle. The stem's bend is shown hugely exaggerated, slowed down.
Stick and slip
The rod's speed along its axis over the last 21 ms (line), and the finger's (dashed). Where they meet, the skin holds the glass: stuck. Then the stem pulls the rod back and it slips, swinging out to the other side and back. Once a cycle the friction's grip and release pump in the energy the stem loses.
Spectrum
live output · markers: the note's harmonics and the stem's other modesSpectrogram
live output · ticks: the spectrum's markersThe note grows in as the finger lands, then holds: one line and its harmonics, which the stick–slip makes and the stem barely resonates. Where a whisker's stretching mode meets a harmonic, it blooms and lingers; as the whiskers sway, the highs sparkle. After the finger lifts the rod rings on for seconds.